Abstract

This study has been performed on the full density sintering of Fe nanopowder and the surface hardening by plasma ion nitriding. The Fe sintered part was fabricated by pressureless sintering of the Fe nanopowder at <TEX>$700^{\circ}C$</TEX> in which the nanopowder agglomerates were controlled to have 0.5-5 <TEX>${\mu}m$</TEX> sized agglomerates with 150 nm Fe nanopowders. The green compact with 46% theoretical density(T.D.) showed a homogeneous microstructure with fine pores below 1 <TEX>${\mu}m$</TEX>. After sintering, the powder compact underwent full densification process with above 98%T.D. and uniform nanoscale microstructure. This enhanced sintering is thought to be basically due to the homogeneous microstructure in the green compact in which the large pores are removed by wet-milling. Plasma ion nitriding of the sintered part resulted in the formation of <TEX>${\gamma}$</TEX>'-<TEX>$Fe_4N$</TEX> equilibrium phase with about 12 <TEX>${\mu}m$</TEX> thickness, leading to the surface hardening of the sintered Fe part. The surface hardness was remarkably increased from 176 <TEX>$H_v$</TEX> for the matrix to 365 <TEX>$H_v$</TEX>.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.